test_exp = ->
run_test [
"exp(-3/4*i*pi)",
#"exp(-3/4*i*pi)",
"-1/2*2^(1/2)-1/2*i*2^(1/2)",
"simplify(exp(-3/4*i*pi))",
#"-1/2*2^(1/2)-1/2*i*2^(1/2)",
"-(1+i)/(2^(1/2))",
]